2,77-0,25=2,52
1/3-1/2 = 2/6-3/6= -1/6
2 5/12 - 17 3/8 = 2 10/24 - 17 9/24= -(16 33/24-2 10/24)= -14 23/24
-29 + 17 1/8= -(28 8/8-17 1/8)= -11 7/8
17-1,25= 15,75
-2,6-7,3=-(2,6+7,3)=-9,9
4 3/4- 4 11/12= 4 9/12-4 11/12 = -(4 11/12-4 9/12 ) = -2/12= -1/6